<!DOCTYPE html>
<html>
<head>
<script type="text/javascript">

function boom()
{
  document.getElementById("q").appendChild(document.createElementNS("http://www.w3.org/1999/xhtml", "td"));
}

</script>
</head>
<body onload="boom();">

<table rules="cols"><thead><tr><th colspan="2"></th></tr></thead><tr></tr><tr id="q" style="border-left: 2px dotted yellow;"></tr></table>

</body>
</html>
